brake pedal travel

[mouchyn]

for those of you with the original vacuum boosters, what does your brake pedal feel like?

I just replaced my master cylinder, but my brakes still feel a little off. The pedal has quite a bit of travel, but it doesn't fade. Once the pedal stops, it stops. That tells me that the master cylinder is holding pressure, but the brake pedal on my sedan moves more than the pedal in my hatchy.

When i lay on the brakes at 60 mph, the car also wants to rotate. I don't know if that means I still have air in the lines somewhere or if the car just handles like that under heavy braking. The stopping power is good, i guess. It'll lock the wheels up just fine and won't fade at all even after a full day at the track. it's just doesn't feel even.

so, is the "mushy" pedal a problem with the 15 year old vacuum booster? with the car off, you can hear a very short "woosh" if you pump the brake pedal.

or is there still air in the lines? I bled all 4 brakes very thoroughly. I flushed all the old fluid out and put in dot 4 fluid. The bleeders pour very clean and clear fluid when I bleed them. That led me to believe that there wasn't any air in the lines, but the brakes don't seem to grab evenly.

slide pins are greased, pads are worn evenly, brakes have been maintained. The rear end just likes to slide around.

again, i guess i'm just used to my preludes. They have all new brake hardware, 4 piston calipers, and braided lines. those brake pedals are rock hard right from the top.

[MrBen]

What kind of brake fluid is in there? I know what you're talking about... I was in an 88 that had very sharp responsive brakes and mine were mushy; it made me jealous. And everything had been replaced and greased in mine with OEM stuff (lines, rotors, brakes, wheels) with the exception of the calipers and master cylinder. I even cleaned everything and it didn't help. So it leads me to believe its the calipers or master cylinder.

Then again if you bought some steel braided brake lines aren't as succeptable to the lines expanding and blowouts. Ever had a blowout? Not fun. Happened to me twice. No thank you, I don't want to experience that again.

The whoosh sound appears to be normal as mine did it and the 88 I was in did it as well. When you pump it 3 times when the car is off, it should cause the pedal to become very firm and incapable of going down. Is this true for you?

I remember a couple times slamming on my brakes to a complete stop on the freeway and having to keep the car from going left or right; it was terrible and I had virtually no control. Not a good feeling.

[mouchyn]

master cylinder is brand new. installed it yesterday. calipers are rebuilt, fresh dot4 brake fluid has been flushed and bled on all 4 corners. the only thing left to replace would be the vacuum booster.

with the car off, you don't even have to pump it three times to make it firm. step on it once, let it come back, and it's already too firm to push again. Master cylinder is rock solid.

start the car, and the pedal will travel a few inches before you get real stopping power. :(

stupid sedan. why did I have to knock my lady up? ;) my preludes and accord hatch were just fine!

[MrBen]

Have you replaced the rear cylinders?

[Oldblueaccord]

master cylinder is brand new. installed it yesterday. calipers are rebuilt, fresh dot4 brake fluid has been flushed and bled on all 4 corners. the only thing left to replace would be the vacuum booster.

with the car off, you don't even have to pump it three times to make it firm. step on it once, let it come back, and it's already too firm to push again. Master cylinder is rock solid.

start the car, and the pedal will travel a few inches before you get real stopping power. :(

stupid sedan. why did I have to knock my lady up? ;) my preludes and accord hatch were just fine!

I dont see why you would have any travel at all.

I would make sure that your rear brakes are adjusted all the way up to the drum. I take them off and on till I can't get the drum on then back it off a scotch. A quick test is drive around with your e-brake up a few clicks see if that gives it the feel you want. The rear coming around is telling me one wheel is locking maybe or there is brake inbalance.

The other thing I am aware that when you change the MC the rod adjustment is pretty critical. My buddys acura was slowly locking the brakes after a long drive. I finally sent it him to my favortite honda mechanic and he adjusted that rod. He told him its what was making his brakes go tighter as he drove.


wp

[mouchyn]

are you talking about the rod between the pedal and the brake booster?

i haven't replaced the rear cylinders. I'll try adjustem them some and see if that helps. the ebrake trick is a good one! never heard of that. good thinkin. I really need to just convert the rears to discs.

if it is an imbalance causing the rear end to wobble, how would i eliminate that? clean out the proportioning valve? I know the right front wheel will lock up before all the others?

maybe bleed the driver's side some more?

[Oldblueaccord]

are you talking about the rod between the pedal and the brake booster?

i haven't replaced the rear cylinders. I'll try adjustem them some and see if that helps. the ebrake trick is a good one! never heard of that. good thinkin. I really need to just convert the rears to discs.

if it is an imbalance causing the rear end to wobble, how would i eliminate that? clean out the proportioning valve? I know the right front wheel will lock up before all the others?

maybe bleed the driver's side some more?

yeah that rod. When it happened to him I looked in the book and I was sure our car had the same set-up BUT I have never taken apart my car so I dont want to swear on it. His was about the same year acura intergra.

You think it started before or after the MC change?

I know you no this but braking should be even, period. you probably got a rotor a little warped. warped drums and rotors lock up a lot easier. A warped drum is hard to feel sometimes since you use the rear brakes so little.

Other than that what bleeding procedure are you using? Im still sold on the 2 man "pump pump hold.....down......ok" method over anything else. I got the mighty vac and all that but I think tried and true is the best. I got my old lady as the "pumper " trained pretty good.

I adjust my rear brakes every couple of months they dont adjust themselves like they should no drum setup does.


wp

[MrBen]

are you talking about the rod between the pedal and the brake booster?

i haven't replaced the rear cylinders. I'll try adjustem them some and see if that helps. the ebrake trick is a good one! never heard of that. good thinkin. I really need to just convert the rears to discs.

if it is an imbalance causing the rear end to wobble, how would i eliminate that? clean out the proportioning valve? I know the right front wheel will lock up before all the others?

maybe bleed the driver's side some more?

I would seriously replace both sides. It's not too expensive. I replaced mine for the hell of it; braking drastically improved as the response was much sharper and not near as spongy.

[mouchyn]

yeah, my fiancee is a trained brake pedal and hydraulic clutch pedal pumper.

the problem started before the MC change. that's why i replaced the MC. It only helped a little. The brakes don't wobble or vibrate at all -- no matter the speed.

I guess i'll just bleed them some more and see what happens. When i get some more cash, i'll be upgrading the rotors and pads. Maybe even converting the rears to discs.

that rod between the pedal and the booster is a pain in the ass to get to. I think you have to remove the cotter pin in holding bolt to separate the arm from the pedal. there's no room up there to do that. that's frustrating. I've already done it once when I converted a friend's 3gee to manual (from auto).

[mouchyn]

i tried the ebrake handle thing and it didn't make a difference in the pedal feel at all. The ebrake holds the car perfectly still on a pretty steep hill, but pulling it up -- even all the way, didn't make a difference in how the pedal felt.

that leads me to believe it's purely a problem with the front brake setup or air still in the lines. sound about right?

just for giggles, would a worn out vacuum booster cause pedal travel like i am experiencing? I've never had trouble with honda vacuum boosters, so I don't know what a worn out booster feels like!

[shepherd79]

you can always bleed the brakes again. just spend some time at each wheel. even tiny little bubles in lines will cause soft pedal.
every time i have soft brake pedal, it is my rear brakes. i take them apart. clean every part. put some antiseize stuff on the things that should move.
make sure the adjuster can move.

[MrBen]

you can always bleed the brakes again. just spend some time at each wheel. even tiny little bubles in lines will cause soft pedal.
every time i have soft brake pedal, it is my rear brakes. i take them apart. clean every part. put some antiseize stuff on the things that should move.
make sure the adjuster can move.

That's a good point. Cleaning the drum brakes did wonders for me. Along with the rear cylinders being replaced ;)

[charlie89LXi]

Does anyone know what the check valve booster is for?
What would happen if this valve fails?
Thanks.